Supercritical reactor systems and processes for petroleum upgrading

ABSTRACT

Supercritical upgrading reactors and reactor systems for upgrading a petroleum-based compositions comprising one or more catalyst layers and, in some embodiments, one or more purging fluid inlets, where one or more catalyst layers at least partially sift and convert heavy hydrocarbon fractions to light hydrocarbon fractions to produce an upgraded supercritical reactor product. In some embodiments, upgrading reactor systems comprise one or more supercritical upgrading reactors and one or more supercritical standby reactors alternating functions such that a supercritical upgrading reactor is converted to a supercritical standby reactor and the supercritical standby reactor is converted to a supercritical upgrading reactor, where the supercritical upgrading reactor upgrades a combined feed stream while a supercritical standby reactor delivers a cleaning fluid into the supercritical standby reactor.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application62/267,406, filed Dec. 15, 2015, which is incorporated by reference inits entirety.

TECHNICAL FIELD

Embodiments of the present disclosure generally relate to upgradingpetroleum-based compositions, and more specifically relate tosupercritical reactor systems, methods, and uses for upgradingpetroleum-based compositions.

BACKGROUND

Petroleum is an indispensable source of energy; however, most petroleumis heavy or sour petroleum, meaning that it contains a high amount ofimpurities (including sulfur and coke, a high carbon petroleum residue).Heavy petroleum must be upgraded before it is a commercially valuableproduct, such as fuel.

Use of supercritical water is effective to upgrade heavy petroleumfeedstock. However, supercritical water reactors generally include twotypes, downflow and upflow reactors, based on the direction thesupercritical water and petroleum-based composition flows. In downflowsupercritical reactors, heavy hydrocarbons fractions flow very quicklydue to higher density, resulting in a shortened residence time (known aschanneling). This may hinder upgrading due to a shortened residence timefor reactions to occur with the higher carbon-containing molecules thattend to reside in the heavier fractions. Upflow supercritical reactorsmay also experience difficulties due to heavy fractions accumulating inthe bottom of the reactor, which may affect the upgrading process andmay plug the reactor.

To combat these deficiencies, catalysts may be used. Among various typesof catalysts, water soluble or organic soluble catalysts may be used toprovide increased contact with the reactants and improve temperaturesand residence times. However, catalysts conventionally exhibit very lowstability in supercritical water conditions. The harsh conditions of thesupercritical reactants often cause breakdown of the catalyst and resultin the formation of insoluble aggregates, which may become seeds forcoke formation. Coke can plug the reactor, slowing or stopping theupgrading process.

SUMMARY

Accordingly, an ongoing need exists to upgrade heavy fractions whileminimizing the formation of pre-coking materials in the process ofupgrading petroleum-based compositions with supercritical reactors.Further, an ongoing need exists to remove pre-coking materials and otherunwanted materials from the catalyst layers of supercritical reactorswithout stopping or delaying the upgrading reaction system process. Thepresent embodiments utilize supercritical reactors to meet these needswhile also discouraging pre-coke formation and removes unwantedmaterials plugging the catalyst layer.

In an embodiment of the disclosure, a process for upgrading apetroleum-based composition comprises combining a supercritical waterstream with a pressurized, heated petroleum-based composition to createa combined feed stream. The combined feed stream is then introduced intoan upgrading reactor system comprising one or more supercriticalupgrading reactors, and is passed through a first catalyst layer, asecond catalyst layer, or both. In the supercritical upgrading reactor,the second catalyst layer is disposed vertically below the firstcatalyst layer and has a greater void volume ratio than the first layer.One or both of the catalyst layers comprise a heterogeneous porous metalcontaining catalyst. The combined feed stream is passed through thefirst catalyst layer and the second catalyst layer, and lighthydrocarbons in the combined feed stream at least partially flow throughthe first catalyst layer and the second catalyst layer while heavyhydrocarbons in the combined feed stream are at least partially siftedin voids of the first catalyst layer, voids of the second catalystlayer, or both. The first catalyst layer, the second catalyst layer, orboth may at least partially convert heavy hydrocarbons to lighthydrocarbons while the light hydrocarbons in the combined feed stream atleast partially flow through one or both catalyst layers. The upgradedproduct comprising light hydrocarbons and converted light hydrocarbonsis then passed out of the supercritical upgrading reactor.

In another embodiment, a process for upgrading a petroleum-basedcomposition comprises combining a supercritical water stream with apressurized, heated petroleum-based composition to create a combinedfeed stream, which is introduced to a supercritical upgrading reactorcomprising at least one catalyst layer. The at least one catalyst layeris a heterogeneous porous metal having a void volume that at leastpartially sifts heavy hydrocarbon fractions in the combined feed streamwhile the light hydrocarbon fractions are allowed to flow through the atleast one catalyst layer. This at least partially converts the heavyhydrocarbon fractions to light hydrocarbon fractions. Purging fluid isinjected through one or more purging fluid inlets into the at least onecatalyst layer and passing an upgraded product out of the supercriticalupgrading reactor.

In another embodiment, a process for upgrading a petroleum-basedcomposition combining a supercritical water stream with a pressurized,heated petroleum-based composition to create a combined feed stream. Thecombined feed stream is then introduced into an upgrading reactor systemcomprising one or more supercritical upgrading reactors and one or moresupercritical standby reactors, where both reactors operate at atemperature greater than the critical temperature of water and apressure greater than the critical pressure of water. Both thesupercritical upgrading reactor and the supercritical standby reactorcomprise at least one catalyst layer having a void volume ratio andcomprising a heterogeneous porous metal containing catalyst. In thesupercritical upgrading reactor, the combined feed stream is upgraded toproduce an upgraded product. While the supercritical upgrading reactoris performing an upgrading step, the supercritical standby reactor isutilizing a cleaning fluid to clean the reactor while in standby mode.The method further comprises alternating the functions of thesupercritical upgrading reactor and the supercritical standby reactor toconvert the supercritical upgrading reactor to a supercritical standbyreactor and to convert the supercritical standby reactor to asupercritical upgrading reactor.

In another embodiment, a reactor for upgrading a petroleum-basedcomposition comprises a first catalyst layer, a second catalyst layerdisposed vertically below the first catalyst layer in the supercriticalreactor, and a plurality of purging fluid inlets disposed proximate tothe first catalyst layer, the second catalyst layer, or both. The firstcatalyst layer and the second catalyst layer comprise at least aheterogeneous porous metal containing catalyst. The first catalyst layercomprises a first void volume ratio and the second catalyst layercomprises at least a second void volume ratio, and the at least a secondvoid volume ratio is lesser than the first void volume ratio.

In another embodiment, a reactor for upgrading a petroleum-basedcomposition comprises a first catalyst layer and a second catalystlayer. The second catalyst layer is disposed vertically below the firstcatalyst layer in the supercritical reactor, and the first catalystlayer and the second catalyst layer comprise at least a heterogeneousporous metal containing catalyst. The first catalyst layer comprises afirst void volume ratio and the second catalyst layer comprises a secondvoid volume ratio where the second void volume ratio is lesser than thefirst void volume ratio.

In yet another embodiment, a reactor for upgrading a petroleum-basedcomposition comprises at least one catalyst layer, where the at leastone catalyst layer comprises a heterogeneous porous metal containingcatalyst having a void volume ratio, and at least one purging fluidinlet disposed proximate the at least one catalyst layer and configuredto deliver purging fluid to the at least one catalyst layer.

Additional features and advantages of the described embodiments will beset forth in the detailed description which follows, and in part will bereadily apparent to those skilled in the art from that description orrecognized by practicing the described embodiments, including thedetailed description which follows, the claims, as well as the appendeddrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of the process for upgrading petroleum-basedcompositions using an upgrading reactor system.

FIG. 2 is a schematic view of a catalyst layer in a supercriticalupgrading reactor.

FIG. 3 is a schematic view of one embodiment of a supercriticalupgrading reactor comprising two catalyst layers.

FIG. 4 is a schematic view of one embodiment of a supercriticalupgrading reactor comprising catalyst layers and two purging fluidinlets.

FIG. 5 is an enlarged schematic view of a purging fluid inlet.

FIG. 6 is a schematic view of one embodiment of a supercriticalupgrading reactor comprising two catalyst layers and two purging fluidinlets.

FIG. 7 is a schematic view of one embodiment of the supercriticalupgrading reactor comprising a catalyst layer and a plurality of purgingfluid inlets.

FIG. 8 is a schematic cross-sectional view of one embodiment of apurging fluid inlet.

FIG. 9 is a schematic cross-sectional view of another embodiment of apurging fluid inlet.

FIG. 10 is a schematic view of an upgrading reactor system with onesupercritical upgrading reactor and a supercritical standby reactor.

FIG. 11 is a schematic overview of the process for upgradingpetroleum-based compositions comprising a supercritical upgradingreactor and a supercritical standby reactor.

DETAILED DESCRIPTION

Embodiments of the present disclosure are directed to supercriticalupgrading reactors and upgrading reactor systems. The embodimentsinclude, among other things, a supercritical upgrading reactorcomprising one or more catalyst layers; a supercritical upgradingreactor comprising one or more catalyst layers and one or more purgingfluid inlets; an upgrading reactor system comprising one or moresupercritical upgrading reactors; and an upgrading reactor systemcomprising one or more supercritical upgrading reactors and one or moresupercritical standby reactors.

As used throughout the disclosure, “supercritical” refers to a substanceat a pressure and a temperature greater than that of its criticalpressure and temperature of water, such that distinct phases do notexist and the substance may exhibit the diffusion of a gas whiledissolving materials like a liquid. At a temperature and pressuregreater than the critical temperature and pressure, the liquid and gasphase boundary of water disappears, and the fluid has characteristics ofboth fluid and gaseous substances. Supercritical water is able todissolve organic compounds like an organic solvent and has excellentdiffusibility like a gas. Regulation of the temperature and pressureallows for continuous “tuning” of the properties of the supercriticalwater to be more liquid or more gas-like. Supercritical water hasreduced density and lesser polarity, as compared to liquid-phasesub-critical water, thereby greatly extending range of potentialreactions that can be carried out in water. Supercritical water is aneffective solvent or diluent in the thermal processing of heavy oil toreduce overcracking or coking.

Without being bound by theory, supercritical water has variousunexpected properties as it reaches supercritical boundaries.Supercritical water has very high solubility toward organic compoundsand has an infinite miscibility with gases. Furthermore, radical speciescan be stabilized by supercritical water through the cage effect (thatis, a condition whereby one or more water molecules surrounds theradical species, which then prevents the radical species frominteracting). The stabilization of radical species may help preventinter-radical condensation and thereby reduces the overall cokeproduction in the current embodiments. For example, coke production canbe the result of the inter-radical condensation. In certain embodiments,supercritical water generates hydrogen gas through a steam reformingreaction and water-gas shift reaction, which is then available for theupgrading reactions.

In the supercritical water process, thermal cracking reactions may becontrolled by the presence of supercritical water to avoid overcrackingand coking. Supercritical water has a very low dielectric constant whichmakes it compatible with common organic solvents such as toluene anddichloromethane. While supercritical water can dissolve a wide range ofhydrocarbons, the high temperature conditions of supercritical water cancause other side reactions before the supercritical water dissolveshydrocarbons. For example, the exposure of benzopyrene to water in hightemperature conditions for a longer period than desirable can cause theformation of coke.

Specific embodiments will now be described with references to thefigures. Whenever possible, the same reference numerals will be usedthroughout the drawings to refer to the same or like parts.

FIG. 1 depicts one embodiment of a process 100 for an upgrading reactorsystem. As shown in FIG. 1, a petroleum-based composition 105 may bepressurized in a pump 112 to create a pressurized petroleum-basedcomposition 116. The pressure of pressurized petroleum-based composition116 may be at least 22.1 megapascals (MPa), which is approximately thecritical pressure of water. Alternatively, the pressure of thepressurized petroleum-based composition 116 may be between 22.1 MPa and32 MPa, or between 23 MPa and 30 MPa, or between 24 MPa and 28 MPa. Insome embodiments, the pressure of the pressurized petroleum-basedcomposition 116 may be between 25 MPa and 29 MPa, 26 MPa and 28 MPa, 25MPa and 30 MPa, 26 MPa and 29 MPa, or 23 MPa and 28 MPa.

The petroleum-based composition 105 may refer to any hydrocarbon sourcederived from petroleum, coal liquid, or biomaterials. Possiblehydrocarbon sources for petroleum-based composition 105 may includewhole range crude oil, distilled crude oil, residue oil, topped crudeoil, product streams from oil refineries, product streams from steamcracking processes, liquefied coals, liquid products recovered from oilor tar sands, bitumen, oil shale, asphaltene, biomass hydrocarbons, andthe like. In a specific embodiment, the petroleum-based composition 105may include atmospheric residue (AR), vacuum gas oil (VGO), or vacuumresidue (VR).

Referring again to FIG. 1, the pressurized petroleum-based composition116 may be heated in one or more petroleum pre-heaters 120 to formpressurized, heated petroleum-based composition 124. In one embodiment,the pressurized, heated petroleum-based composition 124 has a pressuregreater than the critical pressure of water, as previously described,and may have a temperature of greater than 75° C. Alternatively, thetemperature of the pressurized, heated petroleum-based composition 124is between 10° C. and 300° C., or between 50° C. and 250° C., or between75° C. and 200° C., or between 50° C. and 150° C., or between 50° C. and100° C. In some embodiments, the temperature of the pressurized, heatedpetroleum-based stream 124 may be between 75° C. and 225° C., or between100° C. and 200° C., or between 125° C. and 175° C., or between 140° C.and 160° C.

Embodiments of the petroleum pre-heater 120 may include a natural gasfired heater, heat exchanger, or an electric heater or any type ofheater known in the art. In some embodiments, the pressurized, heatedpetroleum-based composition 124 is heated in a double pipe heatexchanger or shell tube heat exchanger later in the process.

As shown in FIG. 1, the water stream 110 may be any source of water,such as a water stream having conductivity of less than 1 microsiemens(μS)/centimeters (cm) such as less than 0.5 μS/cm or less than 0.1μS/cm. The water streams 110 may also include demineralized water,distillated water, boiler feed water (BFW), and deionized water. In atleast one embodiment, water stream 110 is a boiler feed water stream.Water stream 110 is pressurized by pump 114 to produce pressurized waterstream 118. The pressure of the pressurized water stream 118 is at least22.1 MPa, which is approximately the critical pressure of water.Alternatively, the pressure of the pressurized water stream 118 may bebetween 22.1 MPa and 32 MPa, or between 22.9 MPa and 31.1 MPa, orbetween 23 MPa and 30 MPa, or between 24 MPa and 28 MPa. In someembodiments, the pressure of the pressurized water stream 118 may be 25MPa and 29 MPa, 26 MPa and 28 MPa, 25 MPa and 30 MPa, 26 MPa and 29 MPa,or 23 MPa and 28 MPa.

Referring again to FIG. 1, the pressurized water stream 118 may then beheated in a water pre-heater 122 to create a supercritical water stream126. The temperature of the supercritical water stream 126 is greaterthan 374° C., which is approximately the critical temperature of water.Alternatively, the temperature of the supercritical water stream 126 maybe between 374° C. and 600° C., or between 400° C. and 550° C., orbetween 400° C. and 500° C., or between 400° C. and 450° C., or between450° C. and 500° C.

Similar to petroleum pre-heater 120, suitable water pre-heaters 122 mayinclude a natural gas fired heater, a heat exchanger, and an electricheater. The water pre-heater 122 may be a unit separate and independentfrom the petroleum pre-heater 120.

As mentioned, supercritical water has various unexpected properties asit reaches its supercritical boundaries of temperature and pressure. Forinstance, supercritical water may have a density of 0.123 grams permilliliter (g/mL) at 27 MPa and 450° C. In comparison, if the pressurewas reduced to produce superheated steam, for example, at 20 MPa and450° C., the steam would have a density of only 0.079 g/mL. Withoutbeing bound by theory, fluids having a closer density to hydrocarbonsmay react with superheated steam to evaporate and mix into the liquidphase, leaving behind a heavy fraction that may generate coke uponheating. The formation of coke or coke precursor may plug the lines andmust be removed. Therefore, supercritical water is superior to steam insome applications.

Referring again to FIG. 1, the supercritical water stream 126 and thepressurized heated petroleum stream 124 may be mixed in a feed mixer 130to produce a combined feed stream 132. The feed mixer 130 can be anytype of mixing device capable of mixing the supercritical water stream126 and the pressurized heated petroleum stream 124. In one embodiment,feed mixer 130 may be a mixing tee, homogenizing mixer, an ultrasonicmixer, a small continuous stir tank reactor (CSTR), or any othersuitable mixer. The volumetric flow ratio of supercritical water topetroleum fed to the feed mixer 130 may vary to control the ratio ofwater-to-oil (water:oil). In one embodiment, the volumetric flow ratiomay be from 10:1 to 1:10, or 5:1 to 1:5, or 4:1 to 1:1 at standardambient temperature and pressure (SATP). Without being bound by anyparticular theory, controlling the water:oil ratio may aid in convertingolefins to other components, such as iso-paraffins. In some embodiments,the ratio of water:oil may be greater than 1 to prevent the formation ofcoke. In some embodiments, the ratio of water:oil may be less than 5, asdiluting the olefin solution may allow for olefins to pass through thesupercritical upgrading reactor 150 unreacted and the supercriticalupgrading reactor 150 may require additional energy consumption to heatthe large amounts of water if the ratio of water:oil is greater than 10.

Still referring to FIG. 1, the combined feed stream 132 may then beintroduced to the reactor system configured to upgrade the combined feedstream 132. The combined feed stream 132 is introduced through an inletport of the supercritical upgrading reactor 150. The supercriticalupgrading reactor 150 depicted in FIG. 1 is a downflow reactor where theinlet port is disposed near the top of the supercritical upgradingreactor 150 and the outlet port is disposed near the bottom of thesupercritical upgrading reactor 150. Alternatively, it is contemplatedthat the supercritical upgrading reactor 150 may be an upflow reactorwhere the inlet port is disposed near the bottom of the reactor. Adownflow reactor is a reactor where the petroleum upgrading reactionsoccur as the reactants travel downward through the reactor. Conversely,an upflow reactor is a reactor where the petroleum upgrading reactionsoccur as the reactants travel upward through the reactor.

The supercritical upgrading reactor 150 may operate at a temperaturegreater than the critical temperature of water and a pressure greaterthan the critical pressure of water. In one or more embodiments, thesupercritical upgrading reactor 150 may have a temperature of between400° C. to 500° C., or between 420° C. to 460° C. The supercriticalupgrading reactor 150 may be an isothermal or non-isothermal reactor.Moreover, additional components, such as a stirring rod or agitationdevice may also be included in the supercritical upgrading reactor 150.

The supercritical upgrading reactor 150 may have dimensions defined bythe equation L/D, where L is a length of the supercritical upgradingreactor 150 and D is the diameter of the supercritical upgrading reactor150. In one or more embodiments, the L/D value of the supercriticalupgrading reactor 150 may be sufficient to achieve a superficialvelocity of fluid greater than 0.5 meter(m)/minute(min), or an L/D valuesufficient to a achieve superficial velocity of fluid between 1 m/minand 5 m/min. The fluid flow may be defined by a Reynolds number greaterthan 5000.

Referring now to FIG. 2, an enlarged schematic view of a supercriticalupgrading reactor 150 is shown. The supercritical upgrading reactor 150,as shown in FIG. 2, may contain a catalyst layer 210. While theembodiment shown in FIG. 2 has only one catalyst layer 210, it should beunderstood that any number of catalyst layers 210 may be utilized. Insome embodiments, the supercritical upgrading reactor 150 may have twoor more, or three or more, or five or more catalyst layers 210. In someembodiments, the supercritical upgrading reactor 150 may have 10 ormore, or 15 or more, or 20 or more catalyst layers 210.

As shown in FIG. 2, the combined feed stream 132 may be introduced tothe supercritical reactor 150 through an inlet port, which may belocated on the top or bottom of the supercritical upgrading reactor 150.The combined feed stream 132 may both comprise heavy fractions 220 andlight fractions 230.

Heavy fractions 220 may refer to readily insoluble fractions in thecombined feed stream 132. A heavy fraction 220 refers to a hydrocarbonhaving more than 15 carbons. A heavy fraction 220 may include, but isnot limited to asphaltenes, heavy oils, hydrocarbons which areclassified to be lube base oils, other hydrocarbon aggregates,polynuclear aromatics, polyaromatics, long-chain alkyl aromatics,paraffinic waxes, polynaphthalenes, heterorganics, vacuum fractions,atmospheric residue and combinations of these. The heavy fraction 220may comprise a mixture of diesel, vacuum gas oil and vacuum residue, aknown mixture to those of ordinary skill in the industry. A heavyfraction 220 may typically have a boiling point greater than 270° C. Insome embodiments, a heavy fraction 220 may have more than 24 carbons anda boiling point greater than 340° C. The heavy fraction 220 may not besifted through the catalyst layer 210 until it is upgraded into a lightfraction 230. As used throughout the disclosure, “to sift” or “sifted”refers to the selectivity of the pores in the catalyst layer 210 toblock particles by size exclusion. The particles in the light fraction230 may be of a sufficient size to pass through the pores in thecatalyst layer 210, while the particles of the heavy fraction 220 may beblocked by size exclusion until they are broken down to smaller,passable particles.

Light fractions 230 may comprise hydrocarbons with less than 15 carbons.The light fractions 230 in some embodiments will have a molecular weightof less than 210 grams per mole (g/mol) and a boiling point of less than270° C. The molecular weight of 210 g/mol is based on an estimatedcorrelation between molecular weight versus boiling point, specificgravity (density) and viscosity using the “Twu” correlation. The lightfraction 230 may comprise naphtha, kerosene, diesel, and similarcompounds.

As the combined feed stream 132 is passed through the catalyst layer210, the heavy fractions 220 may be at least partially sifted by thecatalyst layer 210. The catalyst layer 210 may at least partiallyupgrade the heavy fractions 220, breaking them down into lightercarbon-containing compounds to form more of the light fraction 230. Thelight fraction 230 may be comprised of lighter, smaller hydrocarboncompounds that are able to pass through the porous catalyst layer 210.The supercritical upgrading reactor product 152 comprises lightfractions 230 which exit the supercritical upgrading reactor 150 throughan outlet port disposed opposite of the inlet port in the supercriticalupgrading reactor 150. In other embodiments, the outlet port may not beopposite of the inlet port, such as an outlet port located on a side ofthe supercritical upgrading reactor 150.

Referring again to FIG. 2, the catalyst layer 210 may comprise, amongother things, a heterogeneous porous metal-containing catalyst material.The catalyst material may be selected from transition metals, includingbut not limited to Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Mo, and alloysthereof. In some embodiments, the catalyst material may be selected fromprecious metals, including but not limited to Au, Ag, Pt, Ru, Rh, Os,and alloys thereof. The catalyst material may comprise a metal that hasbeen coated with another metal, for example, gold coated on titaniummetal. The catalyst material may, in some embodiments, comprisepromoters. The promoters may be selected from alkali and alkaline earthmetals. The promoters may, in some embodiments, comprise K, Li, P, B,and other similar elements. In another embodiment, the catalyst materialmay comprise a nickel-containing alloy. Commercially suitableembodiments include Hastelloy C-276 alloy produced by HaynesInternational, or Inconel-600/625 corrosion resistant alloy, Monel-400nickel copper alloy, and Incoloy-800 corrosion resistant alloy, producedby Specials Metals Corporation. In some embodiments, the catalystmaterial may comprise from 55 wt % to 60 wt % nickel alloy with Mo, Cr,Fe, and W. Without being bound by any particular theory, austeniticnickel-chromium based superalloys may be used to allow the nickel tosurvive the harsh conditions of the supercritical upgrading reactor 150.Furthermore, in some embodiments, the nickel can be oxidized to becomenickel oxide, which may enhance reactions in the supercritical upgradingreactor 150.

As mentioned, conventionally, catalysts are not used in supercriticalreactors due to their instability in supercritical conditions. However,the present embodiments may, in some embodiments, comprise one or morecatalyst layers 210 that do not break down under supercriticalconditions. The one or more catalyst layers 210 may, in someembodiments, react with the heavy fractions 220 to at least partiallyupgrade the heavy fractions 220 to light fractions 230. In someembodiments, the one or more catalyst layers 210 may act similarly to astatic mixer by mixing the heavy fractions 220. Heavy fractions 220 aretypically not readily soluble, even in supercritical water reactors, dueto short residence times and relatively low turbulence. The one or morecatalyst layers 210 may provide additional turbulence by sifting,mixing, chemically reacting the heavy fractions 220, or may utilize anycombination of these techniques to at least be partially upgrade theheavy fractions 220 into light fractions 230.

In some embodiments, the catalyst layer 210 may solid. The catalystlayer 210 may, in some embodiments, be porous or structurally packed invarious suitable arrangements. The woven catalyst layer may have variousweaves and weave structures, for example, catalyst may be characterizedby a mesh structure. For example, the catalyst layer 210 may have aweave structure of 10 mesh (wires per inch) to 400 mesh, or from 20 meshto 200 mesh, or from 40 mesh to 100 mesh. In further examples, thecatalyst layer 210 may comprise metallic honeycombs, sintered metaldisks, and metallic woven cloth. The catalyst layer 210 may have variousweave structures.

In some embodiments, the catalyst material may be treated to activatethe surface of the catalyst layer 210, such as through heat treatment oroxidation. For a non-limiting example, the catalyst material may beheat-treated in air for at least one hour at a temperature greater than400° C. but less than the melting point of the catalyst material beforebeing installed into the supercritical upgrading reactor 150. Thecatalyst material may be heat-treated with an electrical current,microwave, infrared (IR) or ultraviolet (UV) heating to activate orregenerate the catalyst. In some embodiments, the electrical current maybe kept constant through the membrane or wire which may, in someembodiments, be electrically insulated from the supercritical upgradingreactor 150. In some embodiments, an electrical current may reversepoisoning reactions and maintain a regenerated catalyst surface. Withoutbeing bound by any particular theory, heat treatment may generate anoxide, such as nickel oxide, on the surface of the catalyst. Flowingelectric currents, irradiation of IR or UV lights may enhance thesurface oxidation of the catalyst material to form, for instance, a highnickel alloy. Furthermore, in some embodiments the electrical currentmay reverse or prevent poisoning reactions caused by the strongadsorption of sulfur species and large molecules, such as asphaltene andcoke, on the surface of the catalytic material.

In some embodiments, the catalyst layer 210 may be conditioned withsupercritical water at reaction conditions. Conditioning the catalystlayer 210 may remove radical oxygen adsorbed on the catalyst before thecatalyst layer 210 is contacted with the combined feed stream 132. Thecatalyst layer 210 may be conditioned for several hours, such as aperiod of at least more than two hours. The catalyst layer 210 may beconditioned prior to the introduction of the combined feed stream 132into the supercritical upgrading reactor 150. The catalyst layer 210 maybe activated prior to the inclusion in the supercritical upgradingreactor 150. Activation may include oxidation, reduction, and redoxtreatments.

Without intent to be bound by any particular theory, the catalyst layer210 may accelerate a multitude of reactions, including but not limitedto, reforming reactions, gas-water shift reactions, hydrogen donation,hydrogenation, hydrodesulfurization, hydrodenitrogenation, andhydrodemetallization. The catalyst layer 210 may accelerate a reformingreaction, where hydrocarbons react with water to generate hydrogen andcarbon monoxide, which reacts with water to again generate hydrogen andcarbon dioxide, similar to a water-gas shift reaction. The catalystlayer 210 may also accelerate a hydrogen donation reaction, includingwhere hydrogen is extracted from asphaltene in crude oil. The catalystlayer 210 may accelerate hydrogenation reactions, such as thehydrogenation of unsaturated bonds produced from thermal cracking. Thecatalyst layer 210 may additionally accelerate reactions such ashydrodesulfurization, hydrodenitrogenation, or hydrodemetallization, forexample, where hydrogen is generated by a reforming reaction and thehydrogenation removes sulfur, nitrogen, and metals.

Now referring to FIG. 3, another schematic view of an embodiment of asupercritical upgrading reactor 150 is depicted in which thesupercritical upgrading reactor 150 contains an insert 310. Thesupercritical upgrading reactor 150 of this embodiment comprises twocatalyst layers 212, 214. The insert 310 may include a metal tube fitinto the inner diameter of the supercritical upgrading reactor 150. Forexample, the insert 310 may be coaxially disposed within the outer wallsof the supercritical upgrading reactor 150. In one or more embodiments,the insert 310 may be supportive in nature, which may allow a firstcatalyst layer 212 and a second catalyst layer 214 to attach to theouter wall of the supercritical upgrading reactor 150. The insert 310may physically support the catalyst layers 212, 214, and may be removedfor cleaning or easily changed if deformed by the flow of the combinedfeed stream 132. The insert 310 could also be utilized with one catalystlayer 210, as discussed with reference to FIG. 2. Various compositionsare contemplated for the insert 310. In one embodiment, the insert 310may comprise stainless steel, such as Steel Use Stainless (SUS) 316Grade Stainless Steel. The insert 310 may in some embodiments have athickness of 1 mm to 50 mm, or a thickness of 1 mm to 10 mm, or athickness of 5 mm. The thickness of the insert 310 may, in someembodiments, be between 1/100 and 1/10 of reactor inner radius. Theinsert 310 may, in some embodiments, be an annular insert. In someembodiments, the catalyst layers 212, and 214, the purging fluid inlets710, which will be discussed with reference to FIG. 4, or both, maypenetrate through the reactor walls 512 and into the insert 310. In someembodiments, the reactor wall 512 may be an outermost metal tubularwall.

FIG. 3 depicts a supercritical upgrading reactor 150 in a downflowconfiguration, but could alternatively comprise a supercriticalupgrading reactor 150 in an upflow configuration in some embodiments. Aspreviously mentioned with regards to FIG. 2, the combined feed stream132 may comprise heavy fractions and light fractions. As the combinedfeed stream 132 is passed through the first catalyst layer 212, thesecond catalyst layer 214, or both, the heavy fractions are at leastpartially sifted by the catalyst layer 212, 214, or both, and at leastpartially upgraded by the catalyst layer 212, 214, or both, to lightfractions. The light fractions are able to pass through the porouscatalyst layers 212, 214, or both. Once sifted and upgraded, thesupercritical upgrading reactor product 152 exits the supercriticalupgrading reactor 150 through an outlet port disposed opposite of theinlet port. As the molecules must have been small enough to sift throughthe catalyst layers 212, 214, the supercritical upgrading reactorproduct 152 may comprise light fractions and may not comprise heavyfractions. In the embodiment depicted by FIG. 3, the first catalystlayer 212 is the first catalyst layer to encounter the combined feedstream 132. It should be noted that in a supercritical upgrading reactor150 in an upflow configuration, the first catalyst layer 212 may be thebottom-most catalyst layer.

In some embodiments, the first catalyst layer 212 and the secondcatalyst layer 214 may include the same or different compositions. Insome embodiments, the first catalyst layer 212 and the second catalystlayer 214 may include different compositions in order to achievedifferent functionality. Without being bound by theory, the primaryfunction of the first catalyst layer 212 may be cracking large moleculesinto smaller molecules that are passed to the second catalyst layer 214.Meanwhile, the second catalyst layer 214 can have compositions directedto boosting reforming reactions for generating hydrogen, which cantravel through the downflow supercritical upgrading reactor 150. Thesecompositions may include but are not limited to transition metal oxides,such as iron oxides. Hydrogen generated in the second catalyst layer 214can diffuse back to the first catalyst layer 212 to improve the crackingreactions in the first catalyst layer 212.

Still referring to FIG. 3, the first and second catalyst layer, 212 and214, may have different void volume ratios. In some embodiments, thefirst catalyst layer 212 will have a first void volume ratio and thesecond catalyst layer 214 will have a second void volume ratio, whichmay differ or be the same as the first void volume ratio. In one or moreembodiments, the second void volume ratio of the second catalyst layer214 may be greater than or less than the first void volume ratio of thefirst catalyst layer 212. In a further embodiment, the second voidvolume ratio of the second catalyst layer 214 may be less than the firstvoid volume ratio of the first catalyst layer 212. A void volume ratiorefers to the comparison of the volume of the void space in the catalystlayer when compared to the volume of solid surfaces in the catalystlayer. A relatively small void volume ratio indicates that more surfacearea is present in the catalyst layer when compared to a catalyst layerwith a greater void volume ratio. The first catalyst layer 212 may havea greater void volume ratio when compared to the second catalyst layer214, to accommodate large heavy fractions 220 to be upgraded withoutplugging the catalyst layer.

The void volume ratio may be defined as:

${{Void}\mspace{14mu}{Volume}\mspace{14mu}{Ratio}} = {1 - \left( \frac{V_{actual}}{V_{apparent}} \right)}$

In this equation, V_(apparent) refers to the apparent volume of thecatalyst layer while V_(actual) refers to the actual volume of theentire catalyst layer, meaning the volume of the catalyst layerexcluding void spaces and pore volume. Apparent volume refers to thebulk volume as defined in American Society for Testing and Materials(ASTM) Standard D-3766, which is measured by estimating the physicaldimension of the catalyst in accordance with the method described inASTM D-6683. Actual volume refers to the true volume as measured using apycnometer in accordance with ASTM C-604.

The greater void volume ratio of the first catalyst layer 212, whichcontacts the petroleum-based composition 105 feed first, may allow thefirst catalyst layer 212 to have wider pores to sift the large, heavyhydrocarbons from the combined feed stream 132. These sifted heavyhydrocarbons are then cracked into smaller molecules, which mayoptionally be further cracked in the second catalyst layer 214, whichmay have narrower pores than the first catalyst layer 212. In furtherembodiments, it is contemplated to include additional catalyst layers,which may have even narrower pores to allow further cracking andupgrading reactions, thus producing smaller, more upgraded hydrocarbons.

Various void volume ratios are contemplated for the catalyst layers 212and 214. For example, the void volume ratios (based on the equationpreviously discussed) may be from 0.1 to 0.9, or from 0.25 to 0.75, orfrom 0.3 to 0.6, or from 0.35 to 0.5. In one or more downflow reactorembodiments, the ratio of the void volume ratios, that is the voidvolume ratio of the first catalyst layer divided by the void volumeratio of the second layer, is from 1 to 50, or from 1 to 10, or from 1to 5, or from 1 to 2.

Still referring to FIG. 3, the first catalyst layer 212 and the secondcatalyst layer 214 may be in contact with one another or mayalternatively be spaced a distance apart. The first catalyst layer 212and the second catalyst layer 214 may be spaced a part a distance of atleast 10% of the length of the supercritical upgrading reactor 150. Inother embodiments, the first catalyst layer 212 and the second catalystlayer 214 may be spaced a part a distance of at least 5%, or at least8%, or at least 15%, or at least 20%, or at least 30% of the length ofthe supercritical upgrading reactor 150. In some embodiments, the firstcatalyst layer 212 is located at least halfway down the upgradingsupercritical reactor 150 length, such that the first catalyst layer 212is below at least 50% of the reactor volume. In other embodiments, thefirst catalyst layer 212 is located below at least 60% of the reactorvolume, or at least 65% of the reactor volume, or at least 75% of thereactor volume, or at least 80% of the reactor volume. In someembodiments, the first catalyst layer 212 may be from 1 mm to 500 mmaway from the second catalyst layer 214 when measured from the center ofthe first catalyst layer 212 to the center of the second catalyst layer214. In other embodiments, the first catalyst layer 212 may be from 1 mmto 350 mm, or from 1 mm to 200 mm, or from 1 mm to 100 mm away from thesecond catalyst layer 214. In some embodiments, the first catalyst layer212 may touching the second catalyst layer 214, or may be less than 1 mmapart from the second catalyst layer 214.

The first catalyst layer 212 and the second catalyst layer 214 may alsohave similar or different thicknesses and diameters. In someembodiments, first catalyst layer 212 may have a thickness greater thanthe second catalyst layer 214. In other embodiments, the first catalystlayer 212 may have a thickness less than the second catalyst layer 214.The thickness of the catalyst layers 212, 214 may range from less than 1mm to 350 mm, or from 1 to 200 mm, or from 20 to 100 mm, when measuredfrom the top of the catalyst layer 212, 214 to the bottom of thecatalyst layer 212, 214, respectively.

Now referring to FIG. 4, a supercritical upgrading reactor 150 isdepicted in a downflow configuration comprising a purging fluid inlet710. The purging fluid inlet 710 may inject purging fluid 660 into thesupercritical reactor 150 to help reduce plugging in the catalyst layer210. In FIG. 4, a catalyst layer 210 is attached to the reactor walls512 and is supported by an insert 310. FIG. 4 depicts two purging fluidinlets 710 by which purging fluid 660 may be injected into thesupercritical upgrading reactor 150. The heavy fractions may, in someembodiments, cause unwanted plugging of the catalyst layer 210 due totheir large nature and propensity to clump and aggregate. Purging fluid660 may be injected into the catalyst layer 210 to remove materialsembedded in the catalyst layer. The purging fluid 660 may, in someembodiments, comprise supercritical water, supercritical watercontaining non-asphaltenic aromatic hydrocarbons including, but notlimited to, benzene, toluene, xylene, and similar compounds,supercritical water containing product oil, or combinations thereof. Thepurging fluid 660 may, in some embodiments, contain oxygen-containingfluids, such as water saturated with molecular oxygen, water containinghydrogen peroxide (H₂O₂), water containing organic peroxide,hydrocarbons containing organic peroxide, similar compounds, orcombinations of any of these. Without being bound by any particulartheory, flowing oxygen-containing fluids through the system may oxidizecontaminants on the catalyst layer 210 to CO₂ and H₂O, producing orotherwise giving off heat as a reactionary byproduct. FIG. 4 depictsthat in some embodiments, the purging fluid inlets 710 are positionedsuch that the purging fluid 660 flows parallel to the catalyst layer210. This configuration may allow the compounds present in the heavyfraction 220 to flow across the catalyst layer 210 to encourageupgrading reactions.

In some embodiments, the purging fluid 660 may be injected as needed, oron a schedule. The purging fluid 660 may be injected manually orautomatically. In some embodiments of the present invention, the purgingfluid 660 may be injected when the downflow supercritical upgradingreactor 150 experiences a drop in pressure. The pressure of the downflowsupercritical upgrading reactor 150 may, in some embodiments, bemonitored to determine the pressure differential across the catalystlayer 210. The pressure may also be monitored to determine the pressuredownstream of the catalyst layer 210. The pressure differential of thecatalyst layer 210 may indicate that the catalyst layer 210 is clogged.The pressure downstream of the catalyst layer 210 may indicate cloggingof the catalyst layer 210 and is additionally important in monitoringthe reaction scheme, as the supercritical upgrading reactor 150 shouldnot drop below critical pressure.

In some embodiments, purging fluid 660 may be introduced when pressurewithin the reactor deviates from the operating pressure. In someembodiments, the purging fluid 660 may remove plugged material from thecatalyst layer 210 when the pressure has deviated beyond 1%, or beyond3%, or beyond 5%, or beyond 10% of the operating pressure. In someembodiments, the purging fluid 660 may be injected when the pressure hasdeviated less than 2% from the operating pressure, such as less than1.5% or less than 0.5%.

The purging fluid 660 may be injected continuously or intermittently,such as in a stepwise fashion, until an optimal operating pressure isreached. Various pressure measuring devices are contemplated formeasuring the operating pressure. For example, these pressure measuringdevices may include, but are not limited to, pressure gauges, pressuretransducers, pressure sensors, and combinations thereof, may beinstalled at locations where plugging can happen. In one or moreembodiment, the pressure difference should not exceed 10% of operatingpressure (2.5 MPa at 25 MPa or 360 psig at 3611 psig operatingpressure). In one or more embodiments, the purging fluid inlets 710 maybe triggered automatically when the reactor pressure deviates from theoperational pressure by an unacceptable amount.

Still referring to FIG. 4, the purging fluid 660 may, in someembodiments, be heated and pressurized. In one or more embodiments, thetemperature of the purging fluid 660 may be within 200° C. of theinternal fluid temperature of the injection point, or within 150° C. ofthe internal fluid temperature of the injection point, or within 100° C.of the internal fluid temperature of the injection point, or within 50°C. of the internal fluid temperature of the injection point, or within25° C. of the internal fluid temperature of the injection point.Moreover, the pressure of the purging fluid 660 may be a pressure of100% to 120% of the pressure of the internal fluid at the injectionlocation. In this case, if purging fluid 660 is injected into a reactorwhich is operating at approximately 25 MPa at normal unpluggedcondition, the purging fluid 660 may be injected at a pressure in therange of 25 to 30 MPa, which is 100% to 120%, respectively, of thepressure of the internal fluid. Furthermore, the flow rate of thepurging fluid 660 may be injected at a flow rate of 0.001% to 10% of theflow rate of the combined feed stream 132. For example, if the flow rateof internal fluid is 100 liters per hour (L/hr) at standard ambienttemperature and pressure (SATP), the flow rate of the purging fluidshould be in the range of 0.001 to 10 L/hr, which is 0.001% to 50% ofthe flow rate of the combined feed stream 132. The flow rate may bedetermined experimentally through adjustments during operation. The flowrate of the purging fluid and of the supercritical reactor may depend onthe properties of the combined feed stream 132. Factors influencing theflow rate of the purging fluid, the supercritical upgrading reactor 150,or both, may include but are not limited to the amount of pressure inthe supercritical upgrading reactor 150, the composition of the combinedfeed stream 132, the amount of heavy fractions 220 present in thesupercritical reactor, and the positioning and frequency of the purgingfluid inlets 710.

The purging fluid 660, may, in some embodiments, unplug the catalystlayer 210 using chemical means, including, but not limited to using asolvent or a cleaning fluid to dislodge a compound plugging the catalystlayer 210. In other embodiments, the purging fluid 660 may unplug thecatalyst layer 210 using physical means, including, but not limited tousing microturbulence, heat transfer or physical impact to dislodge acompound plugging the catalyst layer.

Again referring to FIG. 4, the purging fluid inlets 710 may be locatedin various positions along the supercritical upgrading reactor 150.There may be one or more purging fluid inlets 710 which may have one ormore ports in which to inject the purging fluid 660. Purging fluidinlets 710 may be used in various embodiments of supercritical upgradingreactors 150 in both downflow and upflow configurations. The purgingfluid inlets 710 may comprise an injection line, such as tubing. In oneor more embodiments, the purging fluid inlets 710 may have an outerdiameter of from 0.1 inches to 4 inches, or from 0.1 inches to 2 inches,or from 0.2 to 0.5 inches. In some embodiments, the purging fluid inlets710 may have an outer diameter of from 1 inch to 3 inches, or from 0.5inches to 2.5 inches, or from 1 inch to 2 inches, or from 0.1 to 1.5inches.

Now referring to FIG. 5, an enlarged schematic view of a purging fluidinlet 710 is shown from an overhead cross-sectional view of thesupercritical upgrading reactor 150. In FIG. 5, the catalyst layer 210is attached directly to the reactor walls 512, such as by welding thecatalyst layer 210 directly to the reactor wall 512. However, it may bedifficult to achieve uniform welding in the reactor, thus, as previouslystated, in some embodiments, an insert 310 may be used. As shown,purging fluid 660 may be sprayed through the purging fluid inlets 710,which may have a plurality of orifices or holes extending along thepipe. While FIG. 5 depicts purging fluid flowing in a direction parallelto the catalyst layer 210, the purging fluid 660 may be directed in anupward, downward, sideways, clockwise, counterclockwise formation or inany combination of these directions. The purging fluid 660 may bedirected in various directions to optimize the removal of embeddedmaterial in the catalyst layer 210 by creating turbulence and agitatingthe combined feed stream 132 comprising the light and heavyhydrocarbons. The diameter and length of the purging fluid inlets 710may be adjusted to produce the desired pressure of purging fluid 660,and will vary in accordance with different embodiments of the presentdisclosure. Moreover, the surface area of the purging fluid inlets 710and purging fluid 660 flow may also vary in accordance with differentembodiments of the present invention.

FIG. 6 is a schematic view of one embodiment of the supercriticalupgrading reactor 150 comprising a plurality of purging fluid inlets 710arranged at multiple levels vertically disposed within the downflowupgrading reactor 150. As shown, one linear purging fluid inlet isdisposed between a first catalyst layer 212 and a second catalyst layer214 and another linear purging fluid inlet is disposed below the secondcatalyst layer 214. That way, if the second catalyst layer 214 isplugged, the purging fluid inlets 710 may inject purging fluid upstreamand downstream of the plugged catalyst layer 214 to remove embeddedmaterial from the top side, the bottom side, or both sides of the secondcatalyst layer 214. Some embodiments of the present disclosure mayutilize a supercritical upgrading reactor 150 with 2 or more purgingfluid inlets 710, such as 3 or more purging fluid inlets 710, or 5 ormore purging fluid inlets 710, or 8 or more purging fluid inlets 710. Insome embodiments, the supercritical upgrading reactor 150 may comprise10 or more, or 15 or more, or even 20 or more or 50 or more purgingfluid inlets 710.

FIG. 7 is a schematic view of another embodiment comprising a pluralityof purging fluid inlets 712 and 714. Specifically, FIG. 7 depicts asupercritical upgrading reactor 150 in a downflow configurationcomprising two varying types of purging fluid inlets used inconjunction. FIG. 7 depicts a linear purging fluid inlet 712 and anon-linear purging fluid inlet 714. Liner purging fluid inlet refers toa straight conduit (for example, straight piping or tubing), which maybe arranged horizontally, vertically, or diagonally at an angle. Incontrast, a non-linear purging fluid inlet 714 refers to a non-straightconduit with at least one bend or curvature along its length. Numerouscombinations of linear purging fluid inlets 712 and non-linear purgingfluid inlets 714 may be utilized, including using only linear purgingfluid inlets 712, using only non-linear purging fluid inlets 714, usingboth linear purging fluid inlets 712 and non-linear purging fluid inlets714, or using neither linear purging fluid inlets 712 nor non-linearpurging fluid inlets 714. Further, embodiments of the present disclosuremay comprise using various combinations of one or more linear purgingfluid inlets 712 to one or more non-linear purging fluid inlets 714,including but not limited to using one linear purging fluid inlet 712and two non-linear purging fluid inlets 714, or vice-versa, using twonon-linear purging fluid inlets 714 and three linear purging fluidinlets 712, or vice-versa, and so on.

Still referring to FIG. 7, as previously mentioned, the non-linearpurging fluid inlets 714 may exhibit one or more bends or one or morecurves. FIG. 7 depicts one embodiment of a non-linear purging fluidinlet 714 with one bend comprising an angle θ, where the angle isdefined relative to plane defined by a straight section of thenon-linear pipe. The angle θ may be any suitable angle, such as anobtuse, acute, or a right (about 90°) angle. In some embodiments, one ormore linear purging fluid inlets 712 may be angled in relation to aplane defined by the catalyst layer. Further, the non-linear purgingfluid inlets 714, linear purging fluid inlets 712, or both, may directthe purging fluid 660 in various directions, including but not limitedto clockwise, counterclockwise, up, down, and combinations of these, aspreviously mentioned.

Referring again to FIG. 7, the linear purging inlet 712 and thenon-linear purging fluid inlet 714 may be operated simultaneously orindependently. In some embodiments of the disclosure, the purging fluidinlets 712 and 714 may be independently controlled and independentlyoperated such that one or more purging fluid inlets 712 and 714 may beoperating while one or more purging fluid inlets 712 and 714 are standbyand non-operational. In some embodiments, the purging fluid inlets 712and 714 may be coordinated to discharge volumes of purging fluid 660from one or more purging fluid inlets 712 and 714 to create turbulenceat the upper surface of the catalyst layer 210. “Turbulence” is used torefer to a conflict or agitation between generally flowing process fluidof the combined feed stream 132 and the purging fluid 660, which mayprevent the catalyst from being rendered ineffective due to a heavyfraction blocking access to the catalyst layer 210 as well as mitigatingadditional catalytic activity in the catalyst layer 210. In someembodiments, the purging fluid 660 may form a countercurrent to unplugthe catalyst layer 210 to sweep heavy fractions across the catalystlayer 210, which may result in both fluid shear and liquid/solid shearas the heavy fractions are raked across the solid, porous surface of thecatalyst layer 210. In some embodiments, the heavy fractions willcounter-circulate, which may cause the heavy fractions to chemically orphysically break due to the increased residence time in thesupercritical environment. In some embodiments, a linear purging fluidinlet 712 may be coordinated with a non-linear purging fluid inlet 714.In some embodiments, this coupling of the purging fluid inlets 712 and714 may prevent a “dead spot” or eddy from occurring against the uppersurface of the catalyst layer 210.

FIG. 8 is a schematic cross-sectional view of a purging fluid inlet 710in relation to the catalyst layer 210 as a cross-sectional view of thesupercritical upgrading reactor 150. In accordance with one embodimentof the present disclosure, the purging fluid inlets 712, 714 mayencircle and surround the catalyst layer 210. The purging fluid 660 maybe injected from purging fluid inlets 712, 714 arranged in an annularring connected to a plurality of linear purging fluid inlets 712. Whilenot shown, the purging fluid inlets 712 and 714 of FIG. 8 may have aplurality of orifices or openings along the annular ring and linearpurging fluid inlets 712 may deliver purging fluid to various locationson the proximate catalyst layer 210.

FIG. 9 is another schematic cross-sectional view of a supercriticalupgrading reactor 150 utilizing another embodiment of a purging fluidinlet 710 in relation to a catalyst layer 210. In accordance withanother embodiment of the present invention, the purging fluid inlet 710may comprise an arrangement of a concentric circle formation inconjunction with a plurality of linear pipes. Many arrangements ofpurging fluid inlets 710 are contemplated depending on the desiredapplication of use and the likelihood and severity of plugging of thecatalyst layer 210.

FIG. 10 is a schematic view of an embodiment of the present disclosuredepicting a process 100 in a supercritical reactor system in which onesupercritical reactor is a supercritical upgrading reactor 150 while theother supercritical reactor is a supercritical standby reactor 140. Asused throughout the disclosure, “standby” refers to a reactor that isnot currently upgrading a combined feed stream 132. FIG. 10 depicts asupercritical upgrading reactor 150 in a downflow configuration, inwhich a combined feed stream 132 is introduced from an inlet in the topof the supercritical upgrading reactor 150 and the supercriticalupgrading reactor product 152 exits from an outlet opposite the inlet.The supercritical upgrading reactor 150 may comprise a catalyst layer210 and an optional insert 310 which may secure the catalyst layer 210to the reactor walls 512.

FIG. 10 depicts a supercritical standby reactor 140 in an upflowconfiguration in which a combined feed stream 132 would enter thereactor through a bottom inlet and the supercritical upgrading reactorproduct 152 would exit from a top opposite the inlet valve. Thesupercritical standby reactor 140 may comprise a catalyst layer 210 andan optional insert 310 which may secure the catalyst layer to thereactor walls 512. The supercritical upgrading reactor 150 and thesupercritical standby reactor 140 may operate separately or inconjunction with one another. In some embodiments, the supercriticalupgrading reactor 150 may be operational while the supercritical standbyreactor 140 is in standby mode, or vice versa. In some embodiments, thesupercritical standby reactor 140 may be flushed with a cleaning fluid.

The cleaning fluid 125 may remove deposits in one or more catalyst layer210. The cleaning fluid 125 may comprise supercritical water. In someembodiments, the cleaning fluid 125 may comprise supercritical watercontaining non-asphaltenic aromatic hydrocarbons, including but notlimited to benzene, toluene, and xylene. The cleaning fluid 125 may bethe same as or a different composition than the purging fluid 660. Thecleaning fluid 125 may be in accordance with any of the embodimentspreviously described with respect to the purging fluid 660. The cleaningfluid 125 could also comprise supercritical water containing product oilor supercritical water containing oxygen. In some embodiments, thesupercritical water containing oxygen may be produced from injecting asolution comprising hydrogen peroxide at standard ambient temperatureand pressure (SATP). The supercritical water may contain an oxygencontent from 0.1 weight percent (wt %) to 2.0 wt %, such as from 0.1 wt% to 0.5 wt %, 0.5 wt % to 1.0 wt %, 1.0 wt % to 1.5 wt %, or 1.5 wt %to 2.0 wt %.

In some embodiments, the supercritical reactors 140 or 150 may alternatebetween being operational and being in a standby mode, such that one ormore supercritical upgrading reactors 150 are operational until one ormore supercritical standby reactors 140 have been cleaned with acleaning fluid 125. In some embodiments, once the cleaning or purging ofthe reactor and the catalyst layers is sufficient, the supercriticalstandby reactor 140 may become operational and become a supercriticalupgrading reactor 150, while the supercritical upgrading reactor 150previously in operational mode would convert to a supercritical standbyreactor 140 for cleaning.

Referring now to FIG. 11, a schematic overview of one embodiment of theprocess 100 for alternating the functionality of the supercriticalupgrading reactor 150 and the supercritical standby reactor 140. LikeFIG. 1, the process 100 of FIG. 11 depicts a supercritical water stream126 and the pressurized heated petroleum stream 124 may be mixed in thefeed mixer 130 to produce a combined feed stream 132. At the same time,a cleaning fluid 115, which may, in some embodiments, be water, ispressurized by pump 113 to produce a pressurized cleaning fluid stream119. The pressurized cleaning fluid stream 119 may then be heated incleaning fluid pre-heater 121 to create a heated, pressurized cleaningfluid 125. The water pre-heater 122, petroleum pre-heater 120, andcleaning fluid pre-heater 121 may exist as independent and separateunits or may comprise one large heating unit.

However, unlike FIG. 1, the combined feed stream 132 of FIG. 11 may passto a flow splitter 137 in communication with a controller unit (forexample, a programmable logic controller (PLC) 145), represented bydotted lines in FIG. 11. In some embodiments, the flow splitter 137 willdirect the combined feed stream 132 to the downflow upgrading reactor150 by opening valve 147, which is upstream of the downflow upgradingreactor 150, and closing valve 148, which is upstream of thesupercritical standby reactor 140. Likewise, the cleaning fluid 125 mayenter a flow splitter 137 in communication with a controller 145. Insome embodiments, the controller 145 may be a programmable logiccontroller (PLC). In some embodiments, the flow splitter 137 will directthe cleaning fluid 125 through open valves 146, which is upstream of thesupercritical standby reactor 140, while closing valve 149, which isupstream of the supercritical upgrading reactor 150.

Further as shown in FIG. 11, the supercritical standby reactor 140 may,in some embodiments, contain one or more pressure sensors 143. Likewise,the supercritical upgrading reactor 150 may contain a pressure sensor141. The pressure sensors 141 or 143 may be upstream or downstream ofthe supercritical upgrading reactor 150, the supercritical standbyreactor 140, or both. Pressure sensors 141 or 143 may include pressuregauges, pressure transducers, or combinations of both. The pressuresensors 141 or 143 may be configured to alert when the pressure of atleast one upgrading reactor has deviated from the operating pressure ofthe supercritical reactor 140 or 150 by at least 1%. In someembodiments, the pressure sensors 141 or 143 may alert when the pressurehas deviated from the operating pressure by at least 0.5%, or at least2%, or at least 3%, or at least 5%, or at least 8% or at least 10%. Thepressure sensors 141 or 143 may be coupled to the controller 145.

Referring again to FIG. 11, if the pressure sensor 141 determines apressure drop within supercritical upgrading reactor 150, indicative ofpossible plugging in the catalyst layer, the pressure sensor 141 willsignal to the controller 145. In response, the controller 145 maytrigger the closure of valve 147, thereby closing the delivery ofcombined feed stream 132 to the supercritical upgrading reactor 150. Atthe same time, the controller 145 may trigger the opening of valve 148,thereby diverting delivery of the combined feed stream 132 to thesupercritical standby reactor 140, which consequently converts theoperation of the supercritical standby reactor 140 from cleaning mode topetroleum upgrading mode. Moreover, the controller 145 will trigger theclosure of valve 149 and the opening of valve 146 which thereby divertscleaning fluid 125 from the supercritical standby reactor 140 to thesupercritical upgrading reactor 150, which consequently converts theoperation of the supercritical upgrading reactor 150 from petroleumupgrading mode to cleaning mode. In some embodiments, cleaning fluid 125is injected until the plugging of the catalyst layer has been remediedand the pressure deviation has been reduced to an acceptable level.

In some embodiments, the controller 145 may cause an alarm or alert totrigger based on the pressure reading transmitted by the pressuresensors 141 or 143. In some embodiments, the alarm or alert may betransmitted to an electronic device, including, but not limited to, acomputer or processor. In other embodiments, the alarm or alert may be asound, flashing light, notification, or other method of indication. Thecontroller 145 may, in some embodiments, automatically cause aninjection of purging fluid 660 in response to the pressure readingstransmitted by the pressure sensors 141 or 143.

It should be apparent to those skilled in the art that variousmodifications and variations can be made to the described embodimentswithout departing from the spirit and scope of the claimed subjectmatter. Thus, it is intended that the specification cover themodifications and variations of the various described embodimentsprovided such modification and variations come within the scope of theappended claims and their equivalents.

Examples

Various features of the present embodiments are illustrated in theExamples below. A simulation was run in accordance with the process 100depicted in FIGS. 1 and 4, in which a petroleum-based composition 105was pressurized in a high pressure metering pump 112 to create apressurized petroleum-based composition 116 with a pressure of 1 literper hour at SATP. The pressurized petroleum-based composition 116 washeated to 150° C. to form a pressurized, heated petroleum-basedcomposition 124. A water stream 110 was pressurized by a high pressuremetering pump 114 to produce pressurized water stream 118 with apressure of 2 liters per hour at SATP. The pressurized water stream 118was then heated in a pre-heater 122 to create a supercritical waterstream 126 at a temperature of 380° C. The supercritical water stream126 and the heated, pressurized petroleum-based composition 124 werecombined in a simple tee fitting mixer to create a combined feed stream132. Referring to FIG. 4, the combined feed stream 132 was thenintroduced into a supercritical upgrading reactor 150 in a downflowconfiguration containing a catalyst layer 210 and multiple purging fluidinlets 710.

The supercritical upgrading reactor 150 was 400 mm in length and 60 mmin diameter with a supportive annular insert 310 having a thickness of 5mm. The supercritical upgrading reactor 150 and insert 310 bothcomprised SUS 316 Grade Stainless Steel. The supercritical upgradingreactor 150 was cylindrical in nature and substantially circular incross section. A tubular heater surrounded the supercritical upgradingreactor and the internal temperature was monitored by a thermocouplelocated in the center of the supercritical upgrading reactor at adistance of 50 mm from the bottom of the supercritical upgrading reactoroutlet valve. The catalyst layer comprised a porous heterogeneouscatalyst containing Hastelloy C-276 high nickel alloy gauze having 40mesh woven, which was located 250 mm from the inlet valve at the top ofthe supercritical upgrading reactor. The wire diameter of the catalystwas 0.19 mm with the opening area at 49%, referring to the open area notoccupied by the wire (for instance, 51 wt % of the mesh is wire and 49wt % of the mesh is open area. The combined feed stream 132 wasintroduced to the catalyst layer 210 via an inlet valve located in thetop of the supercritical upgrading reactor 150. The inlet valve was 0.25inches in outer diameter (0.635 cm) and comprised of SUS 316 GradeStainless Steel pipe.

Tests were performed with and without the porous heterogeneous catalystlayer 210 (Hastelloy C276 high nickel alloy gauze having 40 mesh, woven,0.19 mm diameter) to show upgrading and removal of impurities from ahydrocarbon feedstock. The results of the tests are shown in Table 1 asfollows:

TABLE 1 Petroleum Petroleum Product Product (with (without PropertyFeedstock catalyst) catalyst) API* Gravity degree 12.4 19.5 15.2Distillation  5% 688 550 634 (True Boiling 10% 743 625 701 Point, ° F.)20% 811 710 776 30% 864 763 830 50% 973 845 935 70% 1090 932 1057 80%1154 985 1124 90% 1223 1053 1206 95% 1261 1094 1252 Sulfur Wt % 3.9 3.23.7 Nitrogen Wt. ppm 2037 1450 1670 Asphaltenes Wt % 4.1 0.3 2.8Conradson Wt % 10.4 1.5 8.2 Carbon Vanadium Wt. ppm 50.4 37.2 44.5Nickel Wt. ppm 16.3 5.7 11.5 Average — 556 383 473 Molecular Weight***API refers to the American Petroleum Institute **Average MW is measuredusing VPO (Vapor Pressure Osmometry) to determine the mean relativemolecular mass in accordance with ASTM D-2502

Table 1 shows that the presence of the catalyst increased the extent ofupgrading as well as impurity removal. The remaining amounts of sulfur,nitrogen, asphaltenes, Conradson carbon, vanadium, and nickel arereduced by the addition of a porous heterogeneous catalyst layer to asupercritical water reactor. Surprisingly and unexpectedly, a downflowreactor, which has generally shown poor performance in upgradinghydrocarbons and removing impurities, shows efficient performancebecause of the porous heterogeneous catalyst layer, and the catalystlayer was stable and did not suffer from degradation in the testsperformed.

A first aspect of the present disclosure may be directed to a processfor upgrading a petroleum-based composition that includes combining asupercritical water stream with a pressurized, heated petroleum-basedcomposition in a mixing device to create a combined feed stream;introducing the combined feed stream into an upgrading reactor systemcomprising at least one downflow supercritical upgrading reactoroperating at a temperature greater than a critical temperature of waterand a pressure greater than a critical pressure of water, where thedownflow supercritical upgrading reactor comprises a first catalystlayer and a second catalyst layer, the second catalyst layer disposedvertically below the first catalyst layer in the downflow supercriticalupgrading reactor, where the first catalyst layer is a heterogeneousporous metal containing catalyst having a first void volume ratio andthe second catalyst layer is a heterogeneous porous metal containingcatalyst having a second void volume ratio, where the second void volumeratio differs from the first void volume ratio, and where the downflowsupercritical upgrading reactor includes one or more purging fluidinlets disposed on one or more side locations of the downflowsupercritical upgrading reactor proximate the first catalyst layer, thesecond catalyst layer, or both. The process also includes passing thecombined feed stream through the first catalyst layer and the secondcatalyst layer, where light hydrocarbons in the combined feed stream atleast partially flow through the first catalyst layer and the secondcatalyst layer while heavy hydrocarbons in the combined feed stream areat least partially sifted in voids of the first catalyst layer, voids ofthe second catalyst layer, or both; at least partially converting thesifted heavy hydrocarbons to light hydrocarbons in the first catalystlayer or the second catalyst layer in the presence of the supercriticalwater; injecting purging fluid through the purging inlets to contact thefirst catalyst layer, the second catalyst layer, or both to reduceplugging; and passing upgraded product comprising light hydrocarbons andthe converted light hydrocarbons out of the downflow supercriticalupgrading reactor.

A second aspect of the present disclosure may include the first aspect,in which the second void volume is less than the first void volumeratio.

A third aspect of the present disclosure may include the first andsecond aspects, where the purging fluid inlets are vertically disposedbetween the first catalyst layer and the second catalyst layer.

A fourth aspect of the present disclosure may include any of the firstthrough third aspects, where the purging fluid inlets are verticallydisposed above the first catalyst layer.

A fifth aspect of the present disclosure may include any of the firstthrough fourth aspects, where the purging fluid inlets comprise one ormore angled linear pipes, the angle being relative to a horizontal planedefined by the first catalyst layer.

A sixth aspect of the present disclosure may be directed towards aprocess for upgrading a petroleum-based composition that includescombining a supercritical water stream with a pressurized, heatedpetroleum-based composition in a mixing device to create a combined feedstream, and introducing the combined feed stream into an upgradingreactor system comprising at least one supercritical upgrading reactoroperating at a temperature greater than a critical temperature of waterand a pressure greater than a critical pressure of water. Thesupercritical upgrading reactor comprises a first catalyst layer and asecond catalyst layer, the second catalyst layer disposed verticallybelow the first catalyst layer in the supercritical upgrading reactor,where the first catalyst layer is a heterogeneous porous metalcontaining catalyst having a first void volume ratio and the secondcatalyst layer is a heterogeneous porous metal containing catalysthaving a second void volume ratio, and where the second void volumeratio is lesser than the first void volume ratio. The method alsoincludes passing the combined feed stream through the first catalystlayer and the second catalyst layer, where light hydrocarbons in thecombined feed stream at least partially flow through the first catalystlayer and the second catalyst layer while heavy hydrocarbons in thecombined feed stream are at least partially sifted in voids of the firstcatalyst layer, voids of the second catalyst layer, or both; at leastpartially converting the sifted heavy hydrocarbons to light hydrocarbonsin the first catalyst layer or the second catalyst layer in the presenceof the supercritical water; and passing upgraded product comprisinglight hydrocarbons and the converted light hydrocarbons out of thesupercritical upgrading reactor.

A seventh aspect of the present disclosure may include any of the firstthrough sixth aspects, further comprising activating the first catalystlayer, the second catalyst layer, or both by heating at a temperature ofat least 400° C.

An eighth aspect of the present disclosure may include any of the firstthrough seventh aspects, further comprising conditioning the firstcatalyst layer, the second catalyst layer, or both with supercriticalwater at the temperature and pressure of the upgrading reactor systemprior to introduction of the combined feed stream.

A ninth aspect of the present disclosure may include any of the firstthrough eighth aspects, where the first catalyst layer and the secondcatalyst layer are in contact with one another.

A tenth aspect of the present disclosure may include any of the firstthrough eighth aspects, where the first catalyst layer and the secondcatalyst layer are spaced apart a distance.

An eleventh aspect of the present disclosure may include any of thefirst through eighth and tenth aspects, where a ratio of the first voidvolume ratio to the second void volume ratio is from 1 to 10.

A twelfth aspect of the present disclosure may include any of the firstthrough eleventh aspects, where the first catalyst layer, the secondcatalyst layer, or both comprises one or more structures selected fromthe group consisting of metallic honeycomb, sintered metal disk, ormetallic woven cloth.

A thirteenth aspect of the present disclosure may be directed towards aprocess for upgrading a petroleum-based composition that includescombining a supercritical water stream with a pressurized, heatedpetroleum-based composition in a mixing device to create a combined feedstream, and introducing the combined feed stream into an upgradingreactor system comprising one or more downflow supercritical upgradingreactors operating at a temperature greater than a critical temperatureof water and a pressure greater than a critical pressure of water. Thedownflow supercritical upgrading reactor comprises at least one catalystlayer, where the at least one catalyst layer is a heterogeneous porousmetal containing catalyst having a void volume ratio, and the downflowsupercritical upgrading reactor includes at one or more purging fluidinlet disposed on one or more side locations of the downflowsupercritical upgrading reactor proximate the catalyst layer. The methodalso includes passing the combined feed stream through the catalystlayer, where light hydrocarbons in the combined feed stream at leastpartially flow through the catalyst layer while heavy hydrocarbons inthe combined feed stream are at least partially sifted in the voids ofthe catalyst layer, or both; at least partially converting the blockedheavy hydrocarbons to light hydrocarbons in the catalyst layer in thepresence of the supercritical water; injecting purging fluid through thepurging inlets to contact the first catalyst layer, the second catalystlayer, or both to reduce plugging; and passing upgraded productcomprising light hydrocarbons and the converted light hydrocarbons outof the downflow supercritical upgrading reactor.

A fourteenth aspect of the present disclosure may include any of thefirst through fifth and thirteenth aspects, where the purging fluidinlets comprise one or more linear pipes extending horizontally withinthe downflow supercritical upgrading reactor.

A fifteenth aspect of the present disclosure may include any of firstthrough fifth and thirteenth aspects, where the one or more purgingfluid inlets comprise one or more linear pipes positioned at an angle,the angle being relative to a horizontal plane defined by the firstcatalyst layer.

A sixteenth aspect of the present disclosure may include any of thefirst through fifth and thirteenth aspects, where the one or morepurging fluid inlets comprise one or more non-linear pipes, thenon-linear pipes including at least one bend or curvature relative to astraight section of the non-linear pipe.

A seventeenth aspect of the present disclosure may include the sixteenthaspect, where the bend is oriented at an angle θ relative to a planedefined by a straight section of the non-linear pipe.

An eighteenth aspect of the present disclosure may include theseventeenth aspect, where the angle θ is an acute angle, an obtuseangle, or a 90° angle.

A nineteenth aspect of the present disclosure may include any of thefirst through fifth and thirteenth aspects, where the one or morepurging fluid inlets comprises an annular ring having one or moreopenings.

A twentieth aspect of the present disclosure may include any of thefirst through fifth and thirteenth aspects, where the one or morepurging fluid inlets comprise multiple pipes.

A twenty-first aspect of the present disclosure may include thetwentieth aspect, where the multiple pipes are spaced apart orinterconnected.

A twenty-second aspect of the present disclosure may include any of thefirst through fifth and thirteenth to twenty-first aspects, where theone or more purging fluid inlets have pipes with one or more openings.

A twenty-third aspect of the present disclosure may include any of thefirst through fifth and thirteenth to twenty-second aspects, where thepurging fluid also comprises aromatic hydrocarbons selected from thegroup consisting of benzene, toluene, xylene, and combinations thereof.

A twenty-fourth aspect of the present disclosure may include any of thefirst through twenty-third aspects, further comprising one or morepressure sensors upstream and downstream of the downflow supercriticalupgrading reactor.

A twenty-fifth aspect of the present disclosure may include thetwenty-fourth aspect, where the pressure sensors trigger one the purgingfluid inlets to deliver purging fluid when the pressure of the downflowsupercritical upgrading reactor deviates from 1%-10% of operatingpressure.

A twenty-sixth aspect of the present disclosure is directed to asupercritical upgrading reactor system comprising one or moresupercritical upgrading reactors and one or more supercritical upgradingstandby reactors, in which the one or more supercritical upgradingreactors and the one or more supercritical standby reactors operate at atemperature greater than a critical temperature of water and a pressuregreater than a critical pressure of water; and one or more controllerscoupled to at least one of the one or more supercritical upgradingreactors and at least one of the one or more supercritical standbyreactors, in which the controller allows the supercritical upgradingreactor are the supercritical standby reactor to alternate functions,such that the supercritical standby reactor is converted to asupercritical upgrading reactor that upgrades a combined feed stream andthe supercritical upgrading reactor is converted to a supercriticalstandby reactor that performs a cleaning operation by the delivey of acleaning fluid.

A twenty-seventh aspect of the present disclosure may include thetwenty-sixth aspect, in which at least one of the one or morecontrollers is a programmable logic controller.

A twenty-eighth aspect of the present disclosure is directed towards aprocess for upgrading a petroleum-based composition that includescombining a supercritical water stream with a pressurized, heatedpetroleum-based composition in a mixing device to create a combined feedstream, and introducing the combined feed stream into an upgradingreactor system comprising one or more supercritical upgrading reactorsand one or more supercritical standby reactors. The supercriticalupgrading reactor and the supercritical standby reactor both operate ata temperature greater than a critical temperature of water and apressure greater than a critical pressure of water and the supercriticalupgrading reactor and the supercritical standby reactor both comprise atleast one catalyst layer, where the at least one catalyst layer is aheterogeneous porous metal containing catalyst having a void volumeratio. The method also includes upgrading the combined feed stream inthe supercritical upgrading reactor to produce an upgraded product;cleaning the supercritical standby reactor by passing a cleaning fluidinto the supercritical standby reactor, while the upgrading step isbeing performed in the supercritical upgrading reactor; and alternatingfunctions of the supercritical upgrading reactor and the supercriticalstandby reactor, such that the supercritical upgrading reactor isconverted to a supercritical standby reactor undergoing a cleaningoperation by the delivery of the cleaning fluid, while the supercriticalstandby reactor is converted to a supercritical upgrading reactor thatupgrades the combined feed stream.

A twenty-ninth aspect of the present disclosure may include any of thetwenty-sixth to twenty-eighth aspects, where the heterogeneous porousmetal containing catalyst includes one or more components selected fromthe group consisting of transition metals and precious metals.

A thirtieth aspect of the present disclosure may include thetwenty-ninth aspect, where the transition metals comprise one or moremetal containing components comprising metals selected from the groupconsisting of Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Mo, and combinationsthereof.

A thirty-first aspect of the present disclosure may include thetwenty-ninth aspect, where the precious metals comprise one or moremetal containing components comprising metals selected from the groupconsisting of Au, Ag, Pt, Ro, Rh, Os, and combinations thereof.

A thirty-second aspect of the present disclosure may include any of thetwenty-sixth to thirty-first aspects, where the heterogeneous porousmetal containing catalyst includes metal multilayers or alloys.

A thirty-third aspect of the present disclosure may include any of thetwenty-sixth to thirty-second aspects, where the heterogeneous porousmetal containing catalyst further comprises promoters.

A thirty-fourth aspect of the present disclosure may include any of thetwenty-sixth to thirty-third aspects, further comprising one or morepressure sensors upstream and downstream of the supercritical upgradingreactor, the supercritical standby reactor, or both.

A thirty-fifth aspect of the present disclosure may include thethirty-fourth aspect, where the pressure sensors trigger shutting downthe combined feed stream from the supercritical upgrading reactor andcommencing a cleaning operation.

A thirty-sixth aspect of the present disclosure may include any of thetwenty-sixth to thirty-fifth aspects, where the cleaning fluid comprisessupercritical water.

A thirty-seventh aspect of the present disclosure may include any of thetwenty-sixth to thirty-sixth aspects, where the cleaning fluid comprisessupercritical water and oil.

A thirty-eighth aspect of the present disclosure may include any of thetwenty-sixth to thirty-seventh aspects, where the cleaning fluidcomprises supercritical water and oxygen, where the oxygen content isbetween 0.1 weight percent (wt %) and 2.0 wt %.

A thirty-ninth aspect of the present disclosure is directed towards areactor for upgrading a petroleum-based composition including a firstcatalyst layer, a second catalyst layer disposed vertically below thefirst catalyst layer in the supercritical reactor, and a plurality ofpurging fluid inlets disposed proximate to the first catalyst layer, thesecond catalyst layer, or both, where the first catalyst layer, and thesecond catalyst layer comprises at least a heterogeneous porous metalcontaining catalyst, and where the first catalyst layer comprises afirst void volume ratio, and the second catalyst layer comprises atleast a second void volume ratio, and where the at least a second voidvolume ratio is less than the first void volume ratio.

A fortieth aspect of the present disclosure may include the thirty-ninthaspect, where the reactor comprises an outermost metal tubular wall, andan insert coaxially disposed inside the metal tubular wall.

A forty-first aspect of the present disclosure may include thethirty-ninth or fortieth aspects, where the first catalyst layer, thesecond catalyst layer, and the purging fluid inlets are supported by theinsert.

A forty-second aspect of the present disclosure is directed towards areactor for upgrading a petroleum-based composition including a firstcatalyst layer and a second catalyst layer disposed vertically below thefirst catalyst layer in the supercritical reactor, where the firstcatalyst layer and the second catalyst layer comprise at least aheterogeneous porous metal containing catalyst, where the first catalystlayer comprises a first void volume ratio and the second catalyst layercomprises a second void volume ratio, and where the second void volumeratio is lesser than the first void volume ratio.

A forty-third aspect of the present disclosure may include any of thethirty-ninth to forty-second aspects, where the first catalyst layer andthe second catalyst layer comprise different compositions.

A forty-fourth aspect of the present disclosure may include any of thethirty-ninth to forty-third aspects, where the first catalyst layer andthe second catalyst layer are in contact with one another.

A forty-fifth aspect of the present disclosure may include any of thethirty-ninth to forty-third aspects, where the first catalyst layer andthe second catalyst layer are spaced apart a distance.

A forty-sixth aspect of the present disclosure may include any of thethirty-ninth to forty-third and forty-fifth aspects, where a ratio ofthe first void volume ratio to the second void volume ratio is from 1 to10.

A forty-seventh aspect of the present disclosure may include any of thethirty-ninth to forty-sixth aspects, where the first catalyst layer, thesecond catalyst layer, or both comprises one or structures selected fromthe group consisting of metallic honeycomb, sintered metal disk, andmetallic woven cloth.

A forty-eighth aspect of the present disclosure may include any of theforty-second to forty-seventh aspects, where the reactor comprises anoutermost metal tubular wall, and an insert coaxially disposed insidethe metal tubular wall.

A forty-ninth aspect of the present disclosure may include theforty-eighth aspect, where the first catalyst layer and the secondcatalyst layer are supported by the insert.

A fiftieth aspect of the present disclosure is directed to a reactor forupgrading a petroleum-based composition comprising at least one catalystlayer, where the at least one catalyst layer comprises a heterogeneousporous metal containing catalyst having a void volume ratio, and atleast one purging fluid inlet disposed proximate the at least onecatalyst layer and configured to deliver purging fluid to the at leastone catalyst layer.

A fifty-first aspect of the present disclosure may include the fiftiethaspect, where the catalyst layer comprises one or structures selectedfrom the group consisting of metallic honeycomb, sintered metal disk,and metallic woven cloth.

A fifty-second aspect of the present disclosure may include the fiftiethand fifty-first aspects, where the reactor comprises an outermost metaltubular wall, and an insert coaxially disposed inside the metal tubularwall.

A fifty-third aspect of the present disclosure may include thefifty-second aspect, where the first catalyst layer, the second catalystlayer, and the purging fluid inlets are supported by the insert.

A fifty-fourth aspect of the present disclosure may include any of thethirty-ninth to fifty-third aspects, where the heterogeneous porousmetal containing catalyst of the catalyst layer includes one or morecomponents selected from the group consisting of transition metals andprecious metals.

A fifty-fifth aspect of the present disclosure may include thefifty-fourth aspect, where the transition metals comprise one or moremetal containing components comprising metals selected from the groupconsisting of Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Mo, and combinationsthereof.

A fifty-sixth aspect of the present disclosure may include thefifty-fourth aspect, where the precious metals comprise one or moremetal containing components comprising metals selected from the groupconsisting of Au, Ag, Pt, Ro, Rh, Os, and combinations thereof.

A fifty-seventh aspect of the present disclosure may include any of thethirty-ninth to fifty-sixth aspects, where the heterogeneous porousmetal containing catalyst of the catalyst layer comprises metalmultilayers or alloys.

A fifty-eighth aspect of the present disclosure may include any of thethirty-ninth to fifty-seventh aspects, where the heterogeneous porousmetal containing catalyst further comprises promoters.

A fifty-ninth aspect of the present disclosure may include any of thethirty-ninth to forty-first and fifty to fifty-eighth aspects, where thepurging fluid inlets comprise one or more linear pipes extendinghorizontally within the downflow supercritical upgrading reactor.

A sixtieth aspect of the present disclosure may include any of thethirty-ninth to forty-first and fifty to fifty-eighth aspects, where theone or more purging fluid inlets comprise one or more linear pipespositioned at an angle, the angle being relative to a horizontal planedefined by the first catalyst layer.

A sixty-first aspect of the present disclosure may include any of thethirty-ninth to forty-first and fifty to fifty-eighth aspects, where theone or more purging fluid inlets comprise one or more non-linear pipes,the non-linear pipes including at least one bend or curvature relativeto a straight section of the non-linear pipe.

A sixty-second aspect of the present disclosure may include thesixty-first aspect, where the bend is oriented at an angle θ relative toa plane defined by a straight section of the non-linear pipe.

A sixty-third aspect of the present disclosure may include thesixty-second aspect, where the angle θ is an acute angle, an obtuseangle, or a 90° angle.

A sixty-fourth aspect of the present disclosure may include any of thethirty-ninth to forty-first and fifty to fifty-eighth aspects, where oneor more purging fluid inlets comprises an annular ring having one ormore openings.

A sixty-fifth aspect of the present disclosure may include any of thethirty-ninth to forty-first and fifty to fifty-eighth aspects, where oneor more purging fluid inlets comprises multiple pipes.

A sixty-sixth aspect of the present disclosure may include thesixty-fifth aspect, where the multiple pipes are spaced apart orinterconnected.

A sixty-seventh aspect of the present disclosure may include any of thethirty-ninth to forty-first and fifty to sixty-sixth aspects, where theone or more purging fluid inlets have pipes with one or more openings.

Although the present embodiments have been described in detail, itshould be understood that various changes, substitutions, andalterations can be made without departing from the principle and scopeof the disclosure. Accordingly, the scope of the present disclosureshould be determined by the following claims and their appropriate legalequivalents.

The singular forms “a”, “an” and “the” include plural references, unlessthe context clearly dictates otherwise. Likewise, all ranges may beexpressed throughout as from one particular value, and to anotherparticular value. When such a range is expressed, it is to be understoodthat another embodiment is from the one particular value and to theother particular value, along with all combinations within said range.

What is claimed is:
 1. A process for upgrading a petroleum-basedcomposition comprising: combining a supercritical water stream with apressurized, heated petroleum-based composition in a mixing device tocreate a combined feed stream; introducing the combined feed stream intoan upgrading reactor system comprising at least one downflowsupercritical upgrading reactor operating at a temperature greater thana critical temperature of water and a pressure greater than a criticalpressure of water, where the downflow supercritical upgrading reactorcomprises a first catalyst layer and a second catalyst layer, the secondcatalyst layer disposed vertically below the first catalyst layer in thedownflow supercritical upgrading reactor, where the first catalyst layercomprises a heterogeneous porous metal containing catalyst having afirst void volume ratio and the second catalyst layer comprises aheterogeneous porous metal containing catalyst having a second voidvolume ratio, where the second void volume ratio differs from the firstvoid volume ratio, and where the downflow supercritical upgradingreactor includes one or more purging fluid inlets disposed on one ormore side locations of the downflow supercritical upgrading reactorproximate the first catalyst layer, the second catalyst layer, or both;passing the combined feed stream through the first catalyst layer andthe second catalyst layer, where light hydrocarbons in the combined feedstream at least partially flow through the first catalyst layer and thesecond catalyst layer while heavy hydrocarbons in the combined feedstream are at least partially sifted in voids of the first catalystlayer, voids of the second catalyst layer, or both; at least partiallyconverting the sifted heavy hydrocarbons to light hydrocarbons in thefirst catalyst layer or the second catalyst layer in the presence of thesupercritical water; injecting purging fluid through the purging inletsto contact the first catalyst layer, the second catalyst layer, or bothto reduce plugging; and passing upgraded product comprising lighthydrocarbons and the converted light hydrocarbons out of the downflowsupercritical upgrading reactor.
 2. The process of claim 1, where thesecond void volume ratio is less than the first void volume ratio. 3.The process of claim 2, where the purging fluid inlets are verticallydisposed between the first catalyst layer and the second catalyst layer.4. The process of claim 1, where the purging fluid inlets are verticallydisposed above the first catalyst layer.
 5. The process of claim 1,where the purging fluid inlets comprise one or more angled linear pipes,the angle being relative to a horizontal plane defined by the firstcatalyst layer.
 6. A process for upgrading a petroleum-based compositioncomprising: combining a supercritical water stream with a pressurized,heated petroleum-based composition in a mixing device to create acombined feed stream, introducing the combined feed stream into anupgrading reactor system comprising at least one supercritical upgradingreactor operating at a temperature greater than a critical temperatureof water and a pressure greater than a critical pressure of water, wherethe supercritical upgrading reactor comprises a first catalyst layer anda second catalyst layer, the second catalyst layer disposed verticallybelow the first catalyst layer in the supercritical upgrading reactorwhere the first catalyst layer comprises a heterogeneous porous metalcontaining catalyst having a first void volume ratio and the secondcatalyst layer comprises a heterogeneous porous metal containingcatalyst having a second void volume ratio, and where the second voidvolume ratio is less than the first void volume ratio, passing thecombined feed stream through the first catalyst layer and the secondcatalyst layer, where light hydrocarbons in the combined feed stream atleast partially flow through the first catalyst layer and the secondcatalyst layer while heavy hydrocarbons in the combined feed stream areat least partially sifted in voids of the first catalyst layer, voids ofthe second catalyst layer, or both; at least partially converting thesifted heavy hydrocarbons to light hydrocarbons in the first catalystlayer or the second catalyst layer in the presence of the supercriticalwater; passing upgraded product comprising light hydrocarbons and theconverted light hydrocarbons out of the supercritical upgrading reactor.7. The process of claim 6, further comprising activating the firstcatalyst layer, the second catalyst layer, or both by heating at atemperature of at least 400° C.
 8. The process of claim 6, furthercomprising conditioning the first catalyst layer, the second catalystlayer, or both with supercritical water at the temperature and pressureof the upgrading reactor system prior to introduction of the combinedfeed stream.
 9. The process of claim 6, where the first catalyst layerand the second catalyst layer are in contact with one another.
 10. Theprocess of claim 6, where the first catalyst layer and the secondcatalyst layer are spaced apart a distance.
 11. The process of claim 6,where a ratio of the first void volume ratio to the second void volumeratio is from 1 to
 10. 12. The process of claim 6, where the firstcatalyst layer, the second catalyst layer, or both comprises one or morestructures selected from the group consisting of metallic honeycomb,sintered metal disk, and metallic woven cloth.
 13. The process of claim6, where the downflow supercritical upgrading reactor includes one ormore purging fluid inlet disposed on one or more side locations of thedownflow supercritical upgrading reactor proximate the catalyst layer.14. The process of claim 13, where the purging fluid inlets comprise oneor more linear pipes extending horizontally within the downflowsupercritical upgrading reactor.
 15. The process of claim 13, where theone or more purging fluid inlets comprise one or more linear pipespositioned at an angle, the angle being relative to a horizontal planedefined by the first catalyst layer.
 16. The process of claim 13, wherethe one or more purging fluid inlets comprise one or more non-linearpipes, the non-linear pipes including at least one bend oriented at anangle θ relative to a plane defined by a straight section of thenon-linear pipe or a curvature relative to a straight section of thenon-linear pipe.
 17. The process of claim 13, where the one or morepurging fluid inlets comprises an annular ring having one or moreopenings, multiple pipes spaced apart or interconnected with one or moreopenings, or both.
 18. The process of claim 13, where the purging fluidalso comprises aromatic hydrocarbons selected from the group consistingof benzene, toluene, xylene, and combinations thereof.
 19. The processof claim 13, further comprising one or more pressure sensors upstreamand downstream of the downflow supercritical upgrading reactor.
 20. Theprocess of claim 19, where the pressure sensors trigger one of thepurging fluid inlets to deliver purging fluid when the pressure of thedownflow supercritical upgrading reactor deviates from 1%-10% ofoperating pressure.